The angular distributions of protons in elastic and inelastic scattering by Si and S have been studied, changing the bombarding energy from 4.95 Mev to 5.45 Mev with the interval of 100 Kev. The angular distributions of proton groups from the reaction Si²⁸(p, p′)Si^28* (Q=−1.78 Mev) are nearly symmetric about 90° for any bombarding energy and the total cross-section changes appreciably with the incident energy. On the other hand, the results for the reaction S³²(p, p′)S^32* (Q=−2.24 Mev) show large variation with the energy in both angular distribution and total cross-section. The energy dependence of the angular distribution of elastically scattered protons by silicon is found to be more remarkable than that by sulphur in the energy region studied.

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Angular distributions of protons corresponding to the ground state transition from the reaction ¹²C(α, p)¹⁵N have been measured at twelve energies of alpha particles between 25 and 39 MeV. Each angular distribution shows pronounced diffraction-like patterns, but there exists apparently a systematic shift in the shape and magnitude of angular distributions as the energy changes. At lower energies a sharp rise in the backward angles is observed, while at higher energies it is not observed.
Angular distributions of protons corresponding to some excited state transitions have also been measured at 34.6 MeV.

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The absolute (p, n) cross sections on Ti⁴⁷, Ti⁴⁸, V⁵¹, Cr⁵², Fe⁵⁶, Fe⁵⁷, Ni⁶¹ and Ni⁶⁴ were measured by the activation method at proton energies up to 14 MeV. The experimental results were compared with the predictions based on statistical model in terms of σ(p,n)⁄σ_total, and it was shown that the predictions based on this simple model are not necessarily in disagreement with the experiments.

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The mobility of electrons in n-Ge at an arbitrary field strength is calculated by assuming the distribution function f(p) in the form
f(p)=Aexp\left(−\frac|p+p₀|²2mkT\ ight),
where T is the electron temperature and p₀ represents the uniform displacement of the electron distribution in the direction of the electric field. Two parameters T and p₀ are determined by the same way as Fröhlich and Paranjape did. Interaction constants between electrons and acoustical- and optical-modes of vibration are determined from the temperature dependence of the zero-field mobility. At room temperatures it is found that the electron temperature is determined almost by optical-mode scattering at low fields, but that the energy loss of electrons due to acoustical-mode scattering cannot be neglected at very high fields. Consequently the current density versus electric field relation becomes much different from Shockley’s predictions. It seems that the agreement with the experimental results becomes more satisfactory.

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The properties of the quarternary systems (Sr–Pb)(Ti–Zr)O₃ and (Ba–Pb)(Ti–Sn)O₃ are studied. The shift of transition points with composition is measured by the temperature variation of the dielectric constant of the ceramic sample, and the phase diagrams at room temperature are determined with help of X-ray measurement.
The phase diagram of (Sr–Pb)(Ti–Zr)O₃ includes two ferroelectric phases F_α (rhombohedral) and F_β (tetragonal), two antiferroelectric ones A_α (pseudotetragonal) and A_β (tetragonal) and a paraelectric one P. A_β occupies larger area than expected. The diagram of (Ba–Pb)(Ti–Sn)O₃ resembles that of (Ba–Pb)(Ti–Zr)O₃ previously reported by the author and consists of F₁, F₂ (the same as the low temperature phases in BaTiO₃), F_α, F_β and P, although the immiscible region is found in the composition containing smaller amounts of Ba and Ti.
Roth early classified graphically the perovskite ABO₃ compounds on the basis of electronic polarizability of A ion and ionic radius of B ion. The present author advances this line experimentally by taking up a factor of A ion and one of B ion, using many data already published as well as the present results. The arrangement of A ions nearly agrees with that in terms of the electronic polarizability. Concerning the disposition of B ions, however, the ordering of Ti–Zr–Hf–Sn is adopted, and in addition, Sn and Hf ions are arranged near Zr ion. This diagram may be rather successfully applied to the classification of perovskite A²⁺B⁴⁺O₃ solid solutions.
Furthermore, the possibilities for dielectric and piezoelectric use of the ceramic materials belonging to these systems are examined. Larger dielectric constants are found with certain compositions in (Ba–Pb)(Ti–Sn)O₃, but a striking improvement for PZT ceramics may be rather questionable in both systems.

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The influences of doping on the minute activator diffusion in oxide-coated cathode nickel were measured by a method similar to Swalin and Martin’s and the following conclusions were derived; (1) the influences of doping on the activator diffusion in oxide-coated cathode nickel are significant, (2) as the Mn, Fe, or Si content in oxide-coated cathode nickel increases, the diffusion coefficient of Mg in base nickel decreases monotonously, and (3) as the Mg content in oxide-coated cathode nickel increases, the diffusion coefficient of Mn increases monotonously.

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The current-voltage character and Hall coefficient of n-type InSb with different electron density were measured in a pulsive high electric field, at 77°K. In a high electric field, impact ionization from full band to conduction band occurred and the resistivity and Hall coefficient of n-type InSb decreased rapidly with increasing electric field. In the same region of electric field, Hall mobility decreased and drift velocity reached a maximum value and then decreased. In the curve of the electron density versus μE², the rate of energy gain from electric field, there existed a critical value of μE² where the electron density increased infinitely. This critical value of μE⁴ increased with decreasing electron mobility at low field, and, in one sample, also increased with decreasing strength of the transverse magnetic field.

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Changes with aging time in electrical resistivity and thickness of vacuum deposited gold film were measured on the same specimen. Kiessig’s X-ray interference method was employed for the measurement of film thickness. It was observed that film thickness decreased in exactly the same manner as the resistivity. The proportionality constant between resistivity change and fractional-volume change was about 2.5×10⁻⁴ ohm·cm which agreed well with the quenching experiment of gold in bulk by Bauerle and Koehler, and this suggests that the resistivity change in vacuum deposited gold film at room temperature is predominantly due to a vacancy mechanism just as the case of quenched material in bulk.

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The elastic stiffness constants ||c_ij|| of wurtzite type cadmium sulfide single crystals have been determined on several specimens in the form of cube at room temperature by the ultrasonic pulse echo method at 5.0 and 10 Mc/sec. The results are as follows: c₁₁=0.778; c₁₂=0.447; c₃₃=0.881; c₄₄=0.147; c₆₆=0.159: in units of 10¹² dynes per cm² by using the value of density ρ=4.83 g/cm³.

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The impact test has been carried out on the mechanical twinning of 99.98% pure tin crystals, the time of stressing being 10⁻³ sec. The twinning occurred with a sharp yield process, when the [001] axis was nearly perpendicular (±15°) to the specimen axis. The upper yield stress scattered from 0.7 to 2.5 kg/mm², while the lower yield stress and also the stress for the further thickening of the generated twin lamella were from 0.1 to 0.2 kg/mm².
Twinning occurred where large local stress was expected. The critical shear stress law approximately holds for the upper yield stress after indentation, the stress being 0.8±0.1 kg/mm².
Two explanations for the upper yield stress for twinning appear possible. In the first place, it may be the stress required to initiate the twin with the aid of the local stresses, and in the second place, it may be the stress required for the growth of the nucleated twin lamella across the crystal. It is likely that the growth of the twin nuclei is controlled by the critical shear stress law, and that the growth is suppressed by the appearence of slip.

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The intensity of X-ray beam can be stabilized by using an ionization chamber as a monitor which is placed between an X-ray tube and a specimen. Namely, the filament current of the X-ray tube is controlled so as to keep the output potential of the ionization chamber constant. The ionization chamber was designed in consideration of the response for wavelengths and the statistical fluctuation of the output voltage. Thus, high stability of a demountable X-ray tube as well as of a sealed-off one was obtained without rigorous regulation of tube voltage. If an X-ray tube is operated at 40 kVp and tnbe voltage is stabilized within ±1%, the fluctuation of intensity can be limited to ±0.1%. Then, the fluctuation of intensity in a broad diffraction line of a polycrystalline specimen which was measured for five hours could not be distinguished from the statistical fluctuation. But the fluctuation of intensity in a diffraction line of a single crystal was ±0.2% for the sealed-off tube and ±0.5% for the demountable one.

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A fine focus X-ray tube of the new type was constructed. The electron gun has double wehnelt cylinders. The size of the X-ray source was measured by means of an X-ray pinhole camera. The size of the source becomes very small for the positive value of the bias voltage on the inner cylinder with which the image of the filament is formed on the anode. The finest X-ray source obtained is 40μ in half width and 400μ in length. The peak specific loading is about 8×10⁵W/cm² at the filament temperature 1,700°K which assures long life of the filament.

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The superlattice of spacing about 90 Å in Yu Yen Stone, a variety of serpentine, was studied by electron microscopy (Brindley et al: Acta Cryst. 11 (1958) 99). About 500 electron micrographs showing fringes corresponding to the superlattice were taken, many of which were through-focus series. The intensity profile of fringes varies with the amount of defocus and it also varies from specimen to specimen even at the exact focus. These phenomena are explained qualitatively by theories of image formation. “Extra” terminating half-lines and stepped structures of fringes were studied and it was concluded that the former represent real dislocations in the crystal but the latter are ghosts. The spacing of the superlattice was found not to be constant and this material is not therefore adequate for magnification calibration of electron microscopes (Uyeda et al: J. Phys. Soc. Japan 13 (1958) 461).

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The transition from dynamical to kinematical intensities of electron diffraction from crystals with the change of wave-length of electrons and crystal thickness is theoretically discussed. It is pointed out that the usual treatment of the dynamical theory by the two-wave approximation fails to apply in the range of very short wave-length and small crystal thickness, even with the correction of the dynamical Fourier potential, so that the advent of some convenient treatments taking account of many reflected waves is of essential necessity for consideration of the transition of reflected intensities. It is pointed out, at the same time, that the application of the pseudo-kinematical theory using the complex atomic scattering amplitude calculated on isolated atoms is not permissible in the case of electron diffraction by crystals even for their thinnest limit.

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MnTiO₃ and NiTiO₃ have a rhombohedral crystal structure similar to FeTiO₃ in which layers of Fe and Ti atoms alternate along the rhombohedral axis with oxygen layers between them. A powder neutron diffraction study shows that MnTiO₃ has a magnetic structure with the Mn²⁺ spins antiparallel within each layer. On the other hand, NiTiO₃ has the same magnetic structure as FeTiO₃, in which the spins are parallel within each layer and adjacent layers are antiparallel. The spins are directed along the [111] direction in MnTiO₃ and perpendicular to it in NiTiO₃. In addition to the magnetic study, the nuclear intensities indicate that the Ni and Ti in NiTiO₃ are only 88 per cent ordered.

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This paper describes measurements of the magnetoresistance and of the planar Hall effect of p-type PbTe crystals; it also describes an interpretation of the electronic band structure of the crystal. The measurements were made at 90°K as a function of the magnetic field strength and of the angle between the magnetic field and the current through the specimen. The coefficients relating to the galvanomagnetic effects were determined from the experimental data. Using these coefficients the electronic band structure of the crystal is shown to be {111} energy spheroids, presumably prolate with a mass ratio of 0.3.

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A systematic investigation has been made on the magnetic susceptibility of a series of transition metals dissolved in molten copper at temperatures up to 1600°C. These molten metals are miscible in all proportions except for the Cu-Cr system.
The susceptibilities of the Cu–Co and Cu–Fe alloys follow the Curie-Weiss law. The Curie constant is roughly proportional to the concentration of Co or Fe. The paramagnetic Curie temperature for the Cu–Co system rises monotonously with the concentration of Co, while that for the Cu–Fe system shows a maximum at an intermediate composition. In the Cu–Mn and Cu–Cr systems, only the Cu-rich alloys show the Curie-Weiss paramagnetism, while the alloys containing more than 50% Mn or more than 5% Cr show rather temperature-independent paramagnetism.

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The intrinsic viscosity of a polymeric substance crosslinked as well as degraded by irradiation with high-energy radiations is discussed for various types of initial molecular size distributions. The intrinsic viscosity as a function of radiation dose is shown to behave in a great variety of ways depending on the relative importance of crosslinking and degradation, and in particular, on the shape of the initial distribution. The effect of endlinking instead of crosslinking is also examined.

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There are several impudent assumptions in the determination of molecular weight distributions of high polymers by fractionation. Therefore the reliability of the molecular weight distribution is very problematical. We reconsider the theoretical basis of two fractionation methods, the one is Spencer’s method and the other is the successive precipitation method (SPM). Solving simultaneous integral equations, a modified Spencer’s method is proposed. Though it necessitates to measure the ratio of the volume of the solution phase to that of the precipitated phase, the results are more accurate than Spencer’s method. A modified SPM is also proposed. The results are also compared with the numerical calculation made by other authors and found to be in accord with them.

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A solution of the magnetohydrostatic problem of finding the equilibrium configuration of a plasma in a slightly bending torus tube with circular cross section is reported. Both the plasma and the tube wall are assumed to be perfectly conducting. The ratio of the tube radius to the radius of curvature, R, of the tube axis is assumed to be so small that its square is negligible. The method is an application of a perturbed cylindrical coordinate system, in which the line element ds is given by
ds²=(1−ξR⁻¹rcosθ)²dr²+(1−ηR⁻¹rcosθ)²r²dθ²+(1+R⁻¹rcosθ)²dz²,
ξ and η being functions of γ satisfying ξ=d(rη)⁄dr. A result is the following. If an axially symmetric plasma cylinder with the material pressure monotonically decreasing towards the plasma surface is slightly bent into a torus, then two isobaric surfaces are closer in the more distant part from the torus axis than in the less distant part.

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The photochemical reaction of F→M conversion in an additively colored KCl crystal was investigated as a function of the concentration of F centers, under the condition such as differently colored crystals absorb the equal number of incident photons.
The process of the F band bleaching is separated into two steps of the fast and slow bleaching. During earlier stages of F light irradiation the F band displayed the fast bleaching and its amount in each crystals was equal, and independent on the F center concentration, but the growth rate of the M band was proportional to the square root of the concentration of F center. An absorption band, which may be Petroff’s A band, was induced on the red side of the F band, but the appearance of this band was dominant in the crystal lightly colored. These experimental results show that the mechanism of the optical F→M conversion depends on the F center concentration, and that the M center is converted from the F center through certain intermediate states.
In the case of the F centers converted from U centers, the growth of the M band was small as compared with that of additively colored crystals containing only F centers, and the growth of the A band was also negligibly small.

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Absorption and emission spectra of KI–Tl and NaI–Tl phosphors have been investigated at both room and liquid air temperatures. In order to perform optical measurements on NaI-Tl, special caution was given to prevent the crystal surface from being clouded by moisture. In the absorption spectra of NaI–Tl, new bands due to the presence of thallium were found. Their maximum absorption coefficients seemed to vary with the square of the thallium concentrations. The similar fact has already been found by Yuster and Delbecq in their investigation on KI–Tl. In emission, both KI and NaI crystals containing high concentrations of thallium showed a subsidiary band overlapping the short wavelength tail of the hitherto observed main band. The relations between these absorption and emission bands were investigated and discussions were given in terms of an extended model proposed by Seitz.

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The temperature dependence of the dichroic properties of the M center in KCl crystal was investigated. At the temperatures above 60°C, the thermal reorientation of the M center in the ground state occurs. The measured value of the activation energy for it was 1.0 eV. It was suggested that vacancy clusters may trap free electrons to form new M centers in the course of the bleaching of the M band and this process may be responsible for the temperature dependence of dichroism of the M band.

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The problem of viscous flow near a stagnation point has been exactly solved by Froessling.
In this paper equations of motion for the flow of a visco-elastic liquid near a stagnation point, occurring when a stream of such a liquid impinges on a wall at right angles to it and flows away radially in all directions, have been set up and solved by the Karman-Pohlhausen method. The effect of elasticity is found to depend upon a non-dimensional parameter τ^*=τa (where τ is the flow parameter or the relaxation time constant and a is a constant of dimensions T⁻¹ depending on the velocity in potential flow). Behaviour for small values of this parameter has been studied. It is observed that the boundary layer thickness and the shearing at the wall increase with an increase in τ^*, while the normal stress at the wall is independent of both elasticity and viscosity. The stream lines get closer to the wall with an increase in the parameter.

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The flow of a viscous fluid past an equilateral triangular cylinder has been studied using Imai’s method of treating Oseen’s approximation. The expression for the velocity in the flow field near the triangular cylinder is obtained correct to the order of R², and those for the frictional, pressure and total drag to the order of R. The drag of the triangular cylinder at high Reynolds numbers is estimated by use of Imai’s new theory of drag and is compared with Asaka and Ôshima’s experimental results.

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We sought for the simple relations which exist between the two-dimensional flow of a viscous fluid past a cylindrical obstacle and the flow past the same obstacle rotated by an angle π about its axis, within the accuracy of Oseen’s approximation. It is shown that the forces acting upon the cylinder do not change by the rotation of the cylinder, as far as the terms of order O(R⁻¹) are concerned. Further, for the special cases of symmetrical obstacles which experience no lift, it is shown that the total drags for the original and the rotated bodies coincide with each other within the accuracy of O(R).

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This paper deals with the two-dimensional flow of a viscous, incompressible and electrically conducting fluid past a cylinder in a uniform magnetic field, using Stokes approximation. Detailed calculation is carried out for the flow past a circular cylinder in two cases: one in a parallel magnetic field and the other in a transverse magnetic field. The expansion formulae for the drag per unit span of the cylinder are obtained in terms of the Hartmann number in each case.

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An application of the theory of stochastic processes to the static fracture of non-homogeneous brittle materials such as portland cement concrete is presented. A large number of flexural failure tests on standard mortar specimens made in accordance with JIS have been performed under constant loads as well as under uniformly increasing loads, and the results are analyzed statistically from the standpoint of stochastic theory. It is concluded that the scatter observed in the breaking time or the static strength of concrete appears to be a result of inherent characteristics of the material itself associated with a Markoff process as a kind of rate process.

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